/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla code.
 *
 * The Initial Developer of the Original Code is Mozilla Foundation
 * Portions created by the Initial Developer are Copyright (C) 2011
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Mounir Lamouri <mounir.lamouri@mozilla.com> (original author)
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "nsWindowMemoryReporter.h"
#include "nsGlobalWindow.h"


nsWindowMemoryReporter::nsWindowMemoryReporter()
{
}

NS_IMPL_ISUPPORTS1(nsWindowMemoryReporter, nsIMemoryMultiReporter)

/* static */
void
nsWindowMemoryReporter::Init()
{
  // The memory reporter manager is going to own this object.
  NS_RegisterMemoryMultiReporter(new nsWindowMemoryReporter());
}

static void
AppendWindowURI(nsGlobalWindow *aWindow, nsACString& aStr)
{
  nsCOMPtr<nsIDocument> doc = do_QueryInterface(aWindow->GetExtantDocument());
  nsCOMPtr<nsIURI> uri;

  if (doc) {
    uri = doc->GetDocumentURI();
  }

  if (!uri) {
    nsIPrincipal *principal = aWindow->GetPrincipal();

    if (principal) {
      principal->GetURI(getter_AddRefs(uri));
    }
  }

  if (uri) {
    nsCString spec;
    uri->GetSpec(spec);

    // A hack: replace forward slashes with '\\' so they aren't
    // treated as path separators.  Users of the reporters
    // (such as about:memory) have to undo this change.
    spec.ReplaceChar('/', '\\');

    aStr += spec;
  } else {
    aStr += NS_LITERAL_CSTRING("[system]");
  }
}

NS_MEMORY_REPORTER_MALLOC_SIZEOF_FUN(DOMStyleMallocSizeOf, "windows")

static nsresult
CollectWindowReports(nsGlobalWindow *aWindow,
                     nsWindowSizes *aWindowTotalSizes,
                     nsIMemoryMultiReporterCallback *aCb,
                     nsISupports *aClosure)
{
  // DOM window objects fall into one of three categories:
  // - "active" windows are currently either displayed in an active
  //   tab, or a child of such a window.
  // - "cached" windows are in the fastback cache.
  // - "other" windows are closed (or navigated away from w/o being
  //   cached) yet held alive by either a website or our code. The
  //   latter case may be a memory leak, but not necessarily.
  //
  // For each window we show how much memory the window and its
  // document, etc, use, and we report those per URI, where the URI is
  // the document URI, if available, or the codebase of the principal in
  // the window. In the case where we're unable to find a URI we're
  // dealing with a chrome window with no document in it (or somesuch),
  // and for that we make the URI be the string "[system]".
  //
  // Outer windows are lumped in with inner windows, because the amount
  // of memory used by outer windows is small.
  //
  // The path we give to the reporter callback for "active" and "cached"
  // windows (both inner and outer) is as follows:
  //
  //   explicit/window-objects/top(<top-outer-uri>, id=<top-outer-id>)/<category>/window(<window-uri>)/...
  //
  // The path we give for "other" windows is as follows:
  //
  //   explicit/window-objects/top(none)/window(<window-uri>)/...
  //
  // Where:
  // - <category> is "active" or "cached", as described above.
  // - <top-outer-id> is the window id (nsPIDOMWindow::WindowID()) of
  //   the top outer window (i.e. tab, or top level chrome window).
  // - <top-inner-uri> is the URI of the top outer window.  Excepting
  //   special windows (such as browser.xul or hiddenWindow.html) it's
  //   what the address bar shows for the tab.
  // - <window-uri> is the URI of aWindow.
  //
  // Exposing the top-outer-id ensures that each tab gets its own
  // sub-tree, even if multiple tabs are showing the same URI.

  nsCAutoString windowPath("explicit/window-objects/");

  nsGlobalWindow *top = aWindow->GetTop();
  windowPath += NS_LITERAL_CSTRING("top(");
  if (top) {
    AppendWindowURI(top, windowPath);
    windowPath += NS_LITERAL_CSTRING(", id=");
    windowPath.AppendInt(top->WindowID());
  } else {
    windowPath += NS_LITERAL_CSTRING("none");
  }
  windowPath += NS_LITERAL_CSTRING(")/");

  nsIDocShell *docShell = aWindow->GetDocShell();
  if (docShell) {
    MOZ_ASSERT(top, "'cached' or 'active' window lacks a top window");
    windowPath += aWindow->IsFrozen() ? NS_LITERAL_CSTRING("cached/")
                                      : NS_LITERAL_CSTRING("active/");
  } else {
    MOZ_ASSERT(!top, "'other' window has a top window");
  }

  windowPath += NS_LITERAL_CSTRING("window(");
  AppendWindowURI(aWindow, windowPath);
  windowPath += NS_LITERAL_CSTRING(")");

#define REPORT(_pathTail, _amount, _desc)                                     \
  do {                                                                        \
    if (_amount > 0) {                                                        \
        nsCAutoString path(windowPath);                                       \
        path += _pathTail;                                                    \
        nsresult rv;                                                          \
        rv = aCb->Callback(EmptyCString(), path, nsIMemoryReporter::KIND_HEAP,\
                      nsIMemoryReporter::UNITS_BYTES, _amount,                \
                      NS_LITERAL_CSTRING(_desc), aClosure);                   \
        NS_ENSURE_SUCCESS(rv, rv);                                            \
    }                                                                         \
  } while (0)

  nsWindowSizes windowSizes(DOMStyleMallocSizeOf);
  aWindow->SizeOfIncludingThis(&windowSizes);

  REPORT("/dom", windowSizes.mDOM,
         "Memory used by a window and the DOM within it.");
  aWindowTotalSizes->mDOM += windowSizes.mDOM;

  REPORT("/style-sheets", windowSizes.mStyleSheets,
         "Memory used by style sheets within a window.");
  aWindowTotalSizes->mStyleSheets += windowSizes.mStyleSheets;

  REPORT("/layout/arenas", windowSizes.mLayoutArenas,
         "Memory used by layout PresShell, PresContext, and other related "
         "areas within a window.");
  aWindowTotalSizes->mLayoutArenas += windowSizes.mLayoutArenas;

  REPORT("/layout/style-sets", windowSizes.mLayoutStyleSets,
         "Memory used by style sets within a window.");
  aWindowTotalSizes->mLayoutStyleSets += windowSizes.mLayoutStyleSets;

  REPORT("/layout/text-runs", windowSizes.mLayoutTextRuns,
         "Memory used for text-runs (glyph layout) in the PresShell's frame "
         "tree, within a window.");
  aWindowTotalSizes->mLayoutTextRuns += windowSizes.mLayoutTextRuns;

#undef REPORT

  return NS_OK;
}

typedef nsTArray< nsRefPtr<nsGlobalWindow> > WindowArray;

static
PLDHashOperator
GetWindows(const PRUint64& aId, nsGlobalWindow*& aWindow, void* aClosure)
{
  ((WindowArray *)aClosure)->AppendElement(aWindow);

  return PL_DHASH_NEXT;
}

NS_IMETHODIMP
nsWindowMemoryReporter::GetName(nsACString &aName)
{
  aName.AssignLiteral("window-objects");
  return NS_OK;
}

NS_IMETHODIMP
nsWindowMemoryReporter::CollectReports(nsIMemoryMultiReporterCallback* aCb,
                                       nsISupports* aClosure)
{
  nsGlobalWindow::WindowByIdTable* windowsById =
    nsGlobalWindow::GetWindowsTable();
  NS_ENSURE_TRUE(windowsById, NS_OK);

  // Hold on to every window in memory so that window objects can't be
  // destroyed while we're calling the memory reporter callback.
  WindowArray windows;
  windowsById->Enumerate(GetWindows, &windows);

  // Collect window memory usage.
  nsRefPtr<nsGlobalWindow> *w = windows.Elements();
  nsRefPtr<nsGlobalWindow> *end = w + windows.Length();
  nsWindowSizes windowTotalSizes(NULL);
  for (; w != end; ++w) {
    nsresult rv = CollectWindowReports(*w, &windowTotalSizes, aCb, aClosure);
    NS_ENSURE_SUCCESS(rv, rv);
  }

#define REPORT(_path, _amount, _desc)                                         \
  do {                                                                        \
    nsresult rv;                                                              \
    rv = aCb->Callback(EmptyCString(), NS_LITERAL_CSTRING(_path),             \
                       nsIMemoryReporter::KIND_OTHER,                         \
                       nsIMemoryReporter::UNITS_BYTES, _amount,               \
                       NS_LITERAL_CSTRING(_desc), aClosure);                  \
    NS_ENSURE_SUCCESS(rv, rv);                                                \
  } while (0)

  REPORT("window-objects-dom", windowTotalSizes.mDOM, 
         "Memory used for the DOM within windows. "
         "This is the sum of all windows' 'dom' numbers.");
    
  REPORT("window-objects-style-sheets", windowTotalSizes.mStyleSheets, 
         "Memory used for style sheets within windows. "
         "This is the sum of all windows' 'style-sheets' numbers.");
    
  REPORT("window-objects-layout-arenas", windowTotalSizes.mLayoutArenas, 
         "Memory used by layout PresShell, PresContext, and other related "
         "areas within windows. This is the sum of all windows' "
         "'layout/arenas' numbers.");
    
  REPORT("window-objects-layout-style-sets", windowTotalSizes.mLayoutStyleSets, 
         "Memory used for style sets within windows. "
         "This is the sum of all windows' 'layout/style-sets' numbers.");
    
  REPORT("window-objects-layout-text-runs", windowTotalSizes.mLayoutTextRuns, 
         "Memory used for text runs within windows. "
         "This is the sum of all windows' 'layout/text-runs' numbers.");

#undef REPORT
    
  return NS_OK;
}

NS_IMETHODIMP
nsWindowMemoryReporter::GetExplicitNonHeap(PRInt64* aAmount)
{
  // This reporter only measures heap memory.
  *aAmount = 0;
  return NS_OK;
}